And charles s



J. F. TOOMEY AND C. S. DEMARIzSI'.

SELECTING CIRCUIT FOII ARTIFICIAL LINES.

APPLICATION FILED JUNE I5. I9I7.

7 1,398,725. Patented July 1, 1919.

3 SHEETS SHEET I.

g -II Q M I I an INVENTORS ATTORNEY J. F. TOOMEY AND C. S. DEMAREST.

SELECTING CIRCUIT FOR ARTIFICIAL LINES.

v APPLICATION FILED JUNE I5. I9I7. 1 ,308,725, Patented July 1, 1919.

3 SHEETS-SHEET 2.

7 INVENTORS J1? 7omey6flemamst ATTORNEY J. F. TOOMEY AND C. S. DEMAREST.

SELECTING CIRSUIT FOR ARTIFICIAL LINES.

APPLICATION FILED JUNE 15. 19!].

Patented Jui l, 1919'.

3 SHEETS-SHEET 3.

A TTORNEYS.

riurrsn s'ra rns PATENT @FFICE.

JOHN F. TOOMEY.OF NEW YORK. AND CHARLES S. DEMAREST, OF FLATBUSH, NEW YORK, ASSIGNORS TO AMERICAN TELEPHONE AND TELEGRAPH COMPANY. A

CORPORATION OF 1\TE\V YORK.

SELECTING-CIRCUIT FOR ARTIFICIAL LINES.

artificial line or net-work for balancing a line or trunk with which a repeater is tern-- porarily associated.

It has heretofore been custon'iary when a connection is made between two transmission circuits through a repeater to provide a balancing artificial line or network for each line, said net-works being associated with the repeater. This necessitated either a special repeater circuit having the proper artificiallines or net-works associated therewith for each possible connection between lines of different characteristics, or else a manual switching means whereby the proper artificial line might be temporarily associated with the repeater for each connection. it is proposed by the present invention to provide automatic means, which shall operate, when a repeater is associated with a given transmission circuit, to. associate with the repeater an artificial line of a type suitable for balancing such transmission circuit.

The lines or circuits to be connected through a repeater vary considerably with respect to their impedance characteristics and certain lines may require a special network' for each line while other lines may be grouped into classes or types, the lines of each class having substantially the same im pedance characteristics. In the latter case itis only necessary to provide a suilicient number of net-works of each type for handling the maximum traffic over lines of a given class. Bythis invention it is possible to reduce the number of networks to the I actual trailic requirements by providing for Specification of Letters Patent.

Application filed June 15, 1917.

Patented July 1, 1919.

Serial No. 174,899.

net-works individual to a given repeater circuit but common to a group of lines with each of which a given artificial line is adaptcd to coiiperatc.

Means are provided so that when a repeater is associated with a line requiring an individual artificial line or net-work, the particular artificial line associated with that line is connected to the repeater, and when the repeater is associated with one of a group of 'llIlCS having similar characteristics, an

artificial line individual to the repeater and having characteristics suitable for that group of lines is associated with the repeater and through the repeater with the line.

The invention will be more fully understood by reference to the following description taken in connection with the accompanying drawings, Figures 1, 2 and 3 of which when placed side by side in numerical order constitute a circuit diagram of the invention as applied to a cord circuit repeater.

Referring to F 1, 2 and 3 a plurality of lines or trunks L L l] and L are shown terminating in jacks J J J and J Each of said lines or trunks has an impedance cluu'actcristic which is individual to itself and dill'ers '1' cm the impedance,

charmztcristic or the other lines, therefore necessitating an individual artificial balancing line or net-work for each line of this type. While only four such lines are shown it will be understood that any number of such lines may occur in a given system. trunks L and L. are shown terminating in jacks J and J said lines being illustrative of a group of lines having a common impedance characteristic so that each of the lines of this group may be balanced by the same artificial line or net-worl It will be understood that any number of lines hav- Lines or ing the same impedance may be included in this group. lanes or trunks L and L are shown terminating in jacks J and J,,', said lines being representative of another group of lines or trunks, all having the same impcdauce characteristic and hence capable of being balanced by the same artificial line.

"he impedance of the lines of this roup quay be the same as that of the lines In the group represented by lines L and L or it may be dithn-ent. In the latter case this group will require an artificial balancing line of a different type from that of the of tho linos.

adaptod to oooporato with tho jaolts ot any poator olomonts aro illustratod as hoing of tho \\'oll-l no\\'n moohanioal typo, it is undorstood that tho vaonumtuho typo or any othor typo ot' ropoator may ho omployod it dosn'od.

1n praotioo a sutlioiont numhor ot' ropoat rs I would of oourso, ho prorldod to handlo tho ti'atiio. .\ssooiatod with oaoh lino ot" tho typo ot' linos L, and L L, and i is a oorrospontt ing: h'alanoing altifioial lino or not-work. Thus an artitioial lino X, is proridod to halanoo lino 11,. an artilioial lino Y, to hala'no lino I1 an artitioial lino to halanoo lino L, and an artitioial-lino X, to halanoo lino L 'lho particular moans whorol) tho notworhs aro oonnootod to tho ropoator for halanoing purposos. in aooordanoo with this inroution. is an automatic solooting switch of a typowhioh will ho moro t'ully horoinal'tor dosorihod. Linos snoh as Lal and I T1,, do not roquiro an artitioial lino l'or oaoh transmission lino as all of tho linos of tho sumo typo may ho halanood hy tho samo arti- 'tioial lino and it is only nooossal'y to supply a sullioiont numhor ot artitioial linos to satisty tho tratlio roquiromonts ot' thoso linos. This -may ho oon\'o niontl aooomphshod by providing oaoh ropoator with an artitioial li'io llHllYittllill thoroto. t'or ooiiporation with any ol tho lmos of tho sa mo t-ypo. .\ooordmgly,

an 'artitioial lino or not-work ,X, is asso' oiatod with tho answoring ond of tho oord (-irouit. ropoutor it, wlionoyor a oonnootion is oolnplot'od oroany line of tho. typo of liuos Lo 3'. 'lho al'titioial lino is oonnootod to tho ropoator hy moans of tho automatic switoh alroady rol'orrod to. in a similar mannor ropoator it, is providod with an arti- Iioial lino lt .i\',,. in all rosports similar to artilioial lino RA Individual to tho oalling ond of tho ropoator it, is an artitioial lino. or not-work R,N,- -i t)l' halanoing all linos of tho typo ot' linos l1 L asimilar artitioial lino lt. .l\, boingi assooiatod with tho (ailing ond o't' ropoator R st'ortho-samo purposo. lhoso linos aro oonnootod to thoir rospootivotropoators hy moans ot antomatio so- ]ooting switohos assooiatod with said ropoators.

llaoh rop ator is proridod with an automatio solooting' switoh individual to 'aoh ond thorool'. 'lhus tho'ropoator it, is pro- \'idod with a switoh 5, individual to tho answoringoml thorool and a switoh h, indiyidllal' to tho oalling ond thorool'. -'lhoso s\\"itohos aro illustratod in tho drawing as hoing of 'tliti'oront; typos l'or tho purpose-of disolosing' two modifioations of tho invontion but it. will ho nndorstood that in prao- ,tice switches of thosame type may he used.

Whilo for simplioity t-ho ro- In a similar mannor tho ropoator R is pro- \idod with switohos S and 5 individual to tho answoring and oalling onds'of the repoator rospootiyoly. Switch S, is provided with a sing'lo row ol tost oontaots arrang'od in suoh mannor that a rotatin; wipor may bo oausod to rost upon any ono ot tho oontaots.

This wipor has a normal'or zoro position and whon tho answoring ond of tho ropoatel' is assooiatod with a-oalling lino tho switoh is aotuatod hy moans of a stopping magnet SM, to 'ad anoo stop by stop, oarrying the wipor ovor tho tost oontaots until (it rests upon'tho oontaot oorrosponding to tho all- Zing lino. Whon this ooours a tostv rolay is onorgizod and oausos th'o switoh to stop rotating so that tho wipor romain-s in oontaot with tho tost oontaot oorrospond'ing to the. railing hno and oomplotos a on'ouitfor a An artifioial lino is oonnootod to two oontaots ot' oaoh group. the

third oontaot hoing t'or tost purposos. \Vhon tho railing ond of tho ropoator is assooiatod with a lino to whirh oonnooti'on' is dosirod tho stopping magnot HM, oporatos to adyanooftho wipors ol tho switolr stop by stop oror tho throo rows of oontaots .nntil tho third or tost' wipor is ussooiutod with tho to'st oontaot individual to tho lino oyor whioh tho oonnootion is mado. whoroupon a tost rolay isonorgizod and tho switoh is brought to rost. In a similar mannor a switoh S is 'provldod for tho oalhng ond ot' ropoator R said switoh iNlllQ will all rospoots similar to tho switoh 5/." Artitioial linos suoh 'as N, and X whioh aro individual to oortain lino-s or trunks aro oonnootod in parallol to oorro spondin; oontaots of all of tho. switohos suoh as S, and H ;\'ot-work RA is oonnootod to oontaots ol' switoh. S, only, whilo artilioial lino lt. .i\',, is oonnootod to (()llt:\Ct-- ot' witoh 5', only. .\rtifioial linos suoh as 'X,'..and X whioh aro individual to oortaii'i linos or trunks aro au-h pi'oyidod with parallol oonnootions to tho oontaots ot' oonnooting' rolays individual ,to oaoh of tho switohos, suoh as S, and S. Artificial lino R,N,, is

oonnootod to tho oont'aots ot' a oonnooting rolay'individual to switch S, only, tho artilioiallino R. .N,, hoing oonnoot'od to a oorresponding rolay ot' switoh 3., only.

With this gonoral .dosoription in mind tho oirouits will now ho t'ully undorstood from a description of tho oporation. Assuming that it is desired to connect line L with line L through the repeater R, the operator will P,.in the ack J (onsidering first the operations in connection with the answering end of the repeater a circuit is closed from battery through the winding of relay 10, sleeve contacts of plug P and jack J winding of relay 11 to ground. Relay 10 is energized over this circuit but relay 11 is mar-- ginal so that its winding is not sutiiciently energized by a current'fiowing through the high resistance winding of relay 10 to attract its armature. The operator now actuates the controlling key K whereby battery is connected through a low resistance directly to the sleeve contact of plug I, over the contact 12 of said key. Relay 11 now receives sutiicient current to energize its winding and attracts its armature thereby applying ground to contact 2 of switch S, over a circuit from ground, contact of relay 11, winding and back contact of relay 13, lower back contact and winding of relay 14 to contact 2 of'switch S At the time key K, was actuated a circuit was also closed from ground over the front contact of relay 10,

make contact 15 of key K to point 16 where the circuit divides, one

ath continuing through the winding of olding magnet RM, of switch S to battery, the other path continuing through the winding of relay 17, left hand back contact of relay 18, right tery.- The holding ma hand back contact of test relay 19 and the winding of stepping magnet SM, to batet RM is enerized over this circuit an is so arranged that y its,energization no effect is produced 'upon the switchS but upon being dener- 10 glzed the switch if advanced from normal ositionis'released and restored to norm'al. elay 17 and stepping magnet SM are also energized over-the circuit just traced, the stepping magnet causing the switch to be advanced one step from its zero position so that its wiper 20 is in contact with the first contact of the switch. Relay 17 upon being energized closes a circuit. through the relay 18 which at its right hand front contact. closes a circuit from ground, right hand front contact of relay 18, lower back contact and winding of relay 21 to battery. Relay 21 is thereby energized and at its lower front contact closes a lockin circuit from ground, left hand back contact of test relay 19,

' lower front contact and winding of relay 21 to battery. At its upper contact relay 21 closesza groundcircuit whereby ground is applied to the zero contacts of all of the switches S 8,, etc whereby the test relays v of all switches other than switch S, will be energized to prevent said switches from operating. Relay 18 upon being energized, at its left hand contact opened the circuit previously traced through relay 17 and step- -of relay 19 to battery.

ed contact. In the case oi the connection now being described the second contact is' grounded andupon taking two steps the wiper 20 rests upon contact 2, whereby a circuit is closed from ground, contact of relay 11, winding and back contact of relay 13, lower back contact and winding of relay 14, contact 2 of switch S wiper :50. winding Relays 13, 11 and test relay 19 are energized over this circuit. Relay 13 upon being energized is locked over its front contact at the same time removing the ground which had been applied to the second contacts of all of the switches in parallel. Relay 1% upon being energized closes a locking circuit over its lower front contact, through the winding of said relay, over the second contact of switch S, and wi er 20 thereof and through winding 19 to attery. Relay H at its upper contacts connects the artificial line N to the answering end of the repeater It, to balance the line L,. Test relay 1.) upon being energized,

at its left hand contact opened the locking removing the ground from thezcro contacts of the switches so that the switches of other repeaters are now in condition to be operated if desired. Relay 19 at'its right hand contact opens the circuit previously traced through relay l7-aud stepping magnet SM, so that this circuit is now permanently held open and the stepping magnet SM is no longer actuated to advance the wiper 20 which now remains in contact with the second contact of the switch.

Turning now to the operations in connection with the calling end of the rcpeatcr, upon the insertion of lug P," injack J a circuit is closed from battery, winding of relay 22, sleeve contacts of plug'l, and jack J windingo't' relay 23st) ground. Relay 2:2 is energized overth-is 'circuit but relay 23, like relay 11, is nar inal and is not actuated until the key h, is operated, whereby battery is applied directly through a low resistance over contact 12 of said key to the sleeve contact of plug P, Upon the energization of relay 23, however, ground is connected to the second test contact of switches Sf, S ctc.. over a circuit from ground, contact oi relay 23, winding and back contact oi" relay 24 and thence in parallel to the second test contact of each of the switches. Upon the actuation key K a circuit was also closed from ground. trout contact of relay 22, make contact 25 of key K, to point lfifwhere the-circuit divides, one path continuing through the winding of holdingmagnet 'llM, to battery. the other path continuing -through winding of relay 26, right hand the circuit just traced, the stepping magnet being actuated to advance the three wipers ot' the v switch one step from the zero position so that the wipers rest upon the first set of contacts otthe switch. Relay'QG uponbeing energized closes the circuit. of relay 27'which at'its left hand contact closes a circuit from ground, left hand front contact of a relay 27. lower back contact and windingol relay 29 to battery. Relay 29 is thereby energized andat its lower front contact closes a locking circuit from ground, left hand contact of test relay 28, lower front contact and winding of relay 29 to battery. Relay 2! at its upper contact applies ground to the zero position test contact. of eacli of the switches 5,, S etc. Relay 2? at its right.

'hand contact opens the circuit previously .traced tor relay 2t; and stepping magnet- SM, sothat relay .Zti'is deenergized and opens the circuit of relay 2?, whereby the 'circuit previously traced through relay 2t) and stepping magnet SM, is again closed thereby causing the switch to advance another step.

It: will thus be seen that the. relay 27 operates as a vibrating relay to intermittently close the circuit of the stepping magnet SM,. whereby the switch is advanced step by step until the test wiper 30 thereof rests upon a grounded test contact. In the case now beingalescribed the second test contact is grounded and on taking two steps wiper 3t) rests 'upon this contact, whereby a circuit is closed from ground, lront contact of relay 2 winding and back contact of relay 24, second test contact and wiper 30 of switch Sf, back right hand con tact and winding 01" test 'relay 28 to battery. Test relay 28 and .relay 2 1 are energized over this circuit. relay 24 closing at its front; contact a locking ci'rcuitt'or itsel'l and at the same time disconnecting the grculnd from the second test contact of the various switches 5,, S etc. Test relay 28 upon being energized. its front right hand con tact. closes a locking circuit from battery, whaling and "l'ront right hand contact of relay 2h, winding of relay 31, point lfifmake contact 25 of key K, and trout contact of relay 22 to ground. l telay 31 is energized over this circuit and at its contacts co1nsecond set of contacts.

pletes a circuit whereby the artificial line N is connected to the calling end of the repeater over-the upper pair of the second set of contacts of the switch S Wipers 32 and 33thereof, and the front contacts ofthe relay 31. .Test relay 28 at its middle contact holds open the circuit of the relay 26 and the stepping magnet SM so that the switch remains with its wipers in contact with the Test relay 28 at its left hand contact opens the locking circuit previously traced for relay 29 which is thereby deenergized and removes the ground from the Zero test contacts of the several switches so that the other switches are now ready to be operated if desired.

It will now be seen that lines L and L are interconnected through the repeater R- and that the corresponding artificial lines N 2 and N are connected to the corresponding ends of the repeater by means of switches S and 8,. If new the operator restores the key K upon taking down the connection, the circuits previously traced through the holding magnets RM of switch S and RM, of switch S, are broken so that the holding magnets cause the switches to be restored to normal- As soon as the wiper 20 of switch S is removed from the second contact, the circuit previously traced for test relay 19 is broken and said relay is restored to normal. In the case of switch 8,. the circuit of test relay 28 and connecting relay 31, it will be recalled-was traced through a contact of key K, sothat upon restoring said key these relays are restored to normal. \Vhen the plugs are withdrawn from the jacks relays 1'0, 11, 22. and 23 together with, the circuits controlled thereby are restored to normal. r 7

Had the connection through the repeater R, been made between lines L and L the actuation of the controlling key K would have caused the energization of relays 34 and 35 instead of relays 11 and 23. Relay 34 would have applied ground to the third contacts of each of the switches, S S etci, over a. circuit from ground, front contact of relay 3t, winding and back contact of relay 36 to point37 and thence in parallel thrt'mgh the lower back contact of relays 38, 39, etc, to the third contacts of the switches. The switch S, would therefore have come to rest with its wiper 20 in contact with. the third contact of the switch thereby eompleting a circuit for the relay 38 which would have been energized to connect the artificial line ILV, over its upper contacts to the answering end of the repeater.- If the connection had been made to line L by means of a similar circuit the relay 40 would have been operatedto apply the ground through peater'R the switches S and S to that-already described.

artificial line K N, to the repeater. It will be thus seen that this artificial line will be 4 in parallel to the third test contacts of the switches. Switch 8, would therefore have come to rest with its test wiper Fit) in contact with the third test contact. olsaid switch. thereby extending the connection from the calling end of the repeater over the contacts of relay 31 and wipers 32 and :53 of the. switch Sfl-to the artificial line 11 K Had they-connection been made to the line L by means of a similar circuit ground would again have been applied to the third test contact of the switches and the same result would be brought about. Had the connection been made between any of the lines through the repeater R instead oi rewould analogous In case the repeater R had been connected to line L, or L, the relay 39 would have been actuated to connect the artificial line H N, to the answering end of the repeater and if the re peater had been connected to lines such as L L,,', the artifieial line B N would have been connected over the wipers of switch S to the callingend of the repeater.

By means of the arrangements a'bove described it will be seen that simple and et'ficient means for the automatic selection of an artificial line to balance a transmission line has been provided and while the in vention has been disclosed as embodied in certain forms which are considered desirable, it will be understood that it may be embodied in many widely different organizations without departing from the spirit of the invention.

What is claimed is:

1. The combination with a repeater, of a plurality of tl'tlIlSll'llSSiOl] lines, a plurality of balancing artificial lines, and automatic have been operated in a manner switching means for associatingione of said line. and automatic means for associating said artificial line with said transmission line.

-l. In combination, a transmission line, a. plurality o'l repeaters. a balancimc artificial line for said transmission line. and automatic means responsive to the connection of any out of said l'OPtIl'tIs with said trans-- mission line to associate. the artificial line with the transmission line and said repeater.

5. In combination. a plurality of transmission lines divided into groups, the lines in certain of said groups havingcommon cliaracteristics, the lines in other of said groups having individual characteristics, artificial lines individual to the transmission lines having-individual characteristics, other artificial lines common to the lines of a group having the same clmracteristics, and means for associating" with any transn'iission line an artificial line adapted to balance the same.

(3. In con'ibination, a plurality of trans mission lines divided into groups, the lines in certain oil said groups having common (illitliltttliStitfh, the lines in other of said groups having imlividual charm-teristics, repeaters 't'or interconneoting the lines, artificial lines individual to each ol the lines having individual characteristics, artificial lines individual to the repeaters for balancing any line of a group having, common clnrracteristics, and means for associating with any transmission. line an artificial line adapted peater is asso'ciated with the transmissioi'i line to actuate saio selecting switch to associate the artificial line with the repeater.

S. In combination, a plurality of transmission lines. a plurality of artificial lines less in number than said transmission lines, a. repeater, an automatic selecting switch, and means operative when said repeater is associated with any one of said transmission lines to actuate said switch to select an artificial line to balance the transmission line.

t). in combination, a plurality of transmission lines, a plurality of artificial lines, a repeater, an autoinat ic selecting switch, and means operative when said repeater is assoeluted with any one of said transmission hues to actuate said switch to select 'an l ft/l same cliaracteristies. and an automatic selecting switch for selecting an artificial line adapted to balance any one of said transmission lines. J

11'. In comhination. a plurality of transmission lines divided into groups, the lines in certain of said groups having common characteristics. the lines in other of said groups having individual characteristics, repeaters for interconnccting the lines, art-ificial line individual to each of the lines having individual characteristics. artificial lines individual to the repeaters for h-dancing any line of a group having common characteristics; and an automatic switch responsive to the association of a repeater with a trans" mission line to sele t an artificial line adapt- -1nission lines, a plurality of artificial lines,

a repeater for interconnecting the transmission lines, an autoinatlc selecting switch having a plurality of contacts corresponding to said artificial lines, means controlled by each transmission line when a repeater is asst ci condition of one of said contacts correspondto an artificial line adapted to balance said transmission line, means responsive to the association of a repeater with a transal therewith for changing the electrical mission line for causing said switch to select such contact. and means to connect the artificial line correspomling to said contact to the repeater when said contact is selected.

. l-l. In combination. a plurality of trans- .mission lines divided into groups. thelincs of certain of said groups having the same 'characteristics, artificial lilies individual to of said artificial lines. means controlled by each of the lines having an individual arti licial line for rendering the Contact 'corrosponding to its artificial line selectable. and means whereby any of the lines of a group having a common artificial line may render the contact corresponding to said line selectahle.

15. In combination, a plurality of transmission lines, a plurality of artificial lines, a plurality of repeaters, 't'or interc'onnee-ting the transmissionlines. 'an automatic selecting switch associatedwith each repmiter, means operative when a repeater is asso ciated with a transmission line, to cause the corresponding switch to' select an artificial line to balance the transmission line; and. means to render the switches of other repeaters inoperative while the switch of one repeater is maltin a selection.

' In testimony whereot we have signed our names to this specification this seventh day of June 1917.

JOHN I TOOMEY. CHARLES S. DEMAREST. 

